Atomizing nozzles, also called mist heads, are used in connection with misting systems to produce fog or at least a fine mist. Typically, water under pressure is forced through the atomizing nozzles to produce the mist. Desirably, the mist is sufficiently fine so that it rapidly evaporates. As the mist evaporates, the general area around the atomizing nozzles becomes cooler. Rapid evaporation prevents people and property located in the mist from getting wet and enhances the cooling effect. Accordingly, misting systems are often used for cooling and for increasing humidity.
In order to produce a fog or at least a fine mist that quickly evaporates, atomizing nozzles include a small orifice through which a fluid, such as water, under high pressure passes as it exits the nozzle. In addition, a plunger, also called a poppet or impeller, is positioned within a passage that connects to the orifice. The action of the plunger within the passage helps break the fluid into a fog or fine mist.
FIG. 1 shows a cross sectional side view of a prior art atomizing nozzle 20. Nozzle 20 has a conventional cylindrically shaped plunger 22 residing in a passage 24 of nozzle 20. Passage 24 has an inlet end 26 for receiving the fluid to be atomized, and an outlet end 28 for ejecting the atomized fluid. Conventionally, following installation of cylindrical plunger 22 into passage 24, an orifice-bearing plug 30 is press-fit into passage 24 from outlet end 28 of prior art nozzle 20. Orifice-bearing plug 30 prevents cylindrical plunger 22 from escaping from passage 24 through outlet end 28. A retaining element (not shown) may also be implemented to prevent cylindrical plunger 22 from escaping from inlet end 26.
FIG. 2 shows a cross sectional side view of the position of cylindrical plunger 22 in prior art atomizing nozzle 20 when impacted by a pressurized fluid 32. As pressurized fluid 32 flows into inlet end 26 of atomizing nozzle 20, it impacts cylindrical plunger 22 driving it toward outlet end 28. Fluid 32 flows around cylindrical plunger 22 through spaces 34 between plunger 22 and the walls of passage 24. Due to the cylindrical shape of plunger 22, as fluid 32 drives plunger 22 toward outlet end 28, plunger 22 can get wedged in passage 24 such that an axial dimension of plunger 22 is not parallel with the axial dimension of passage 24.
This wedged position of cylindrical plunger 22 is highly undesirable because fluid 32 does not flow through spaces 34 around cylindrical plunger in a uniform flow pattern. This non-uniform flow pattern produces an unsatisfactory mist 36 that is subsequently ejected from outlet end 28. Mist 36 is unsatisfactory because mist 36 includes fluid particles having a wide range of diameters. As a result, a substantial proportion of the fluid particles are not effectively evaporated and the larger fluid particles cause the general area around prior art nozzle 20 to become wet.
In addition, the wedged position of cylindrical plunger 22 prevents plunger 22 from rotating or spinning within passage 24. Thus, a problem is created because residual mineral materials contained in fluid 30 will be deposited on the immobile and wedged cylindrical plunger 22 after prolonged use. These deposited materials can partially block passage 24 so that fluid particles in mist 36 become much larger and are much less effectively evaporated.
Typically, orifice-bearing plug 30 is pressed into place in outlet end 28 with great force so that a fluid tight seal results even when fluid 30 is placed under great pressure. Since retaining ring 30 is press-fit with such great force, it cannot thereafter be removed for subsequent cleaning of passage 24 to remove the deposited mineral materials.
In time, these deposited mineral materials will eventually completely block passage 24 so that prior art nozzle 20 is no longer able to eject mist 36. Accordingly, conventional atomizing nozzles are expensive to acquire and become clogged before long due, in part, by the immobile and wedged position of the conventional cylindrical plunger. The blocked nozzles must then be thrown away because they cannot be unclogged and replacement nozzles must be purchased and installed.